Discussion Forum



Please study each questions below and all the three statements, numbered I, II and III, and decide whether any information provided in the statement(s) is redundant and can be dispensed with while answering the given question.

1)

How much time will the train $A$ take to cross another train $B$ running in opposite direction ?

I. Train $A$ crosses a signal pole in $6$ seconds.

II. Ratio of the speed of train $A$ and $B$ is $3:2$

III. Length of the two trains together is $500$ metres.


A) I only

B) II only

C) III only

D) I or II only

E) Question cannot be answered with all I, II and III.

Answer:

Option E

Explanation:

II. Let the speeds of $A$ and $B$ be $3x$ m/sec and $2x$ m/sec

I. length of train $A$ $=(3x\times 6)$ m $=18x$ metres.

III. Length of train B $=(500-18x)$ m.

Relative speed $=(3x+2x)$ m/sec $=5x$ m/sec.

Thus, even with the information in all the three statements, question cannot be answered.

$\therefore$ Correct answer is (E).